1. He had discovered a great law of human action without knowing it — namely, that in order to make a man or a boy desire a thing, it is only necessary to make the thing difficult to attain.
    他不知不觉发现了人类行为的一个伟大的定律——那就是，若要使人追求一物，只要让它难以到手就行了。

2. Humboldt was a great letter-writer.
    洪堡是一位伟大的书信撰写家。

3. He met up with my great-grandfather on my mother's side, who introduced him to the toodle, and before long, people were coming to his shop for sandwiches more than they were coming for meat.
    他偶然碰到了我的外曾祖父，知道了芥末筒这东西。没过多久，到他的店里来买三明治的人比来买肉的人更多了。

4. Despite her great age, she was very graceful indeed.
    尽管她上了年纪,但体态确实优美.

5. And we have to lower into the ground and haul out of the ground great lengths of drill pipe which are rotated by an engine at the top and are fitted with a cutting bit at the bottom.
    我们必须把很长的钻杆一节节地钻入地下，然后再从地下拉出来。钻杆顶部安装的发动机带动钻杆旋转，它的底部装有钻头。

6. Despite her great age, she was very graceful indeed,
    尽管上了年纪，但体态确实优美。

7. Dunant´s book was a great success.
    杜兰特的书获得了极大的成功。

8. And Polly (波莉), my grandmother, who perfected a brush to clean the inside of a water tap.
    还有波莉，就是我的外祖母，她改进了一把刷子用来清洁水龙头的内部。

9. Athens is a city of great antiquity.
    雅典是一座古城.

10. About 2,300 years ago, there lived in Greece a great thinker named Aristotle.
    大约两千三百年以前, 在希腊住着一位名叫亚里斯多德的伟大的思想家.